Wednesday, December 2, 2015

Northern Sea Otter


The Northern Sea Otter
By Olga Esmeral

What is a Northern Sea Otter?

The Northern sea otter (Enhyra ultras kenyoni) is the largest species in the mustelid family, and is one of the smallest marine mammals. Adults may grow up to 5 feet in length, males weighing  80–100 lbs. and females 50–70 lbs. It has unique adaptations, allowing it to thrive in the nearshore marine environment. As the only marine mammal species that lacks a blubber layer, it is dependent on a dense coat of fur for insulation from cold water. They have a pretty high metabolic rate that helps them maintain body temperature. This requires them to consume large amounts of prey, as much as 20-33% of their body weight each day. This diet mainly consists of benthic invertebrates. Their habitat is generally in or near shallow water. The threatened population includes the Southwest Alaska Distinct Population Segment.

Range


Sea otters do not migrate long distances. They usually stay in a home range that could consists of a few square km up to 40 km2. The northern sea otter subspecies (E. lutris kenyoni), is found in the Aleutian Islands, Southern Alaska, British Columbia, and Washington. There are 3 stocks in Alaska. The Southeast stock is in the coastal waters of Southeast Alaska. The southcentral population goes from west of Glacier Bay to the eastern edge of Cook Inlet. The Southwest population stretches from the western edge of Cook Inlet out the Aleutian islands. 



What Happened to the Cutest Marine Mammal?

The estimated population of sea otters worldwide was once between several hundred thousand to over one million before to almost facing extinction by hunting of fur traders in the 1700s and 1800s. Sea otters eventually gained protection from International Fur Seal Treaty of 1911, and became listed under the Marine Mammal Protection and Endangered Species Acts in the 1970s. Based on survey information that showed the southwest Alaska population of northern sea otters had declined by more than 50% since the mid- 1980s, the U.S. Fish and Wildlife Service (FWS) listed this distinct population segment (DPS) as threatened in August 2005.

The Bad Guys
  1.  Most important are predation (moderate to high importance) and oil spills (low to moderate importance).
  2.  Increased predation is caused most likely by the killer whale (Orcinus orca)                                  
  3. Infectious disease, biotoxins, contaminants, food limitation, disturbance, bycatch in fisheries, subsistence harvest, loss of habitat, and illegal take, are also considered in this recovery plan.   
Road to Recovery  
Goal of the recovery plan is to control or reduce threats to the southwest Alaska DPS of the northern sea otter to the extent that it no longer needs protection by the ESA and can be delisted. To attain this goal there are 3 objectives:
  1.      Establish a self-sustaining population of sea otters in each management unit
  2.          Maintain enough sea otters to assure a functional role in nearshore ecosystem
  3.      Mitigate threats sufficiently to guarantee persistence of sea otters.       

Extras:
  •             Monitoring the status of the kelp forest ecosystem in the Western Aleutian and Eastern Aleutian MUs. 
  •              identifying characteristics of sea otter habitat, and ensuring that efficient oil spill response capability exist in southwest Alaska. 
  •              Predation is considered to be the most important threat to recovery, additional research on that topic is also a high priority
  •            Total cost: $15 million 


Let's Take Action
Due to oil spills being significant factors in the overall threat towards the Northern Sea Otter, I plan on using less oil and oil-based products to decrease oil pollution in sea otter habitats. Some simple ways of cutting down include switching to vegetable and fruit-based detergents and household cleaners, using paper bags and avoiding plastic and Styrofoam packaging, and walking or biking to short destinations more often in the place of driving. 

Want to make a small donation that could go a long way towards Northern Sea Otter recovery? You can join Defenders of Wildlife and adopt a sea otter through donation! https://secure.defenders.org/site/SPageServer?pagename=wagc_seaotter&s_src=3WEW1600XXXXX&s_subsrc=120215_adopt_body_sea-otter/how-you-can-help

References:
Deborah. "How the Expensive Fur of the Sea Otter Is Secured." Scientific
American 56.1452supp (1903): 23263. How Can I Help the Sea Otter? Friends of
the Sea Otter, 28 Mar. 2009. Web. 1 Dec. 2015. 
"Northern Sea Otter Species Profile, Alaska Department of Fish and Game." Northern
Sea Otter Species Profile, Alaska Department of Fish and Game. State of
Alaska, n.d. Web. 02 Dec. 2015.
"Threats to Sea Otters." Wild Places and Wildlife. Defenders of Wildlife, 19 Mar. 2012.
Web. 02 Dec. 2015.
"Southwest Alaska DPS of the Northern Sea Otter Recovery Plan." 2013. Endangered
Species Recovery Plans. US Fish and Wildlife, 25 June 2013. Web. 23 Nov.

2015.

2 comments:

  1. Sea Otters are awesome animals and I never knew they had no layer of blubber. It's crazy to think there were over a million otters at one point, and now they're barely any left. I think it's a fantastic idea to reduce our consumption of oil-based products in order to help protect this animal. This was a really informative blog and I really liked it! #BIO227Fall2015

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  2. I love sea otters! This blog post was very informative especially in the personal action aspect- I'm glad I can take immediate steps in my personal life, both financially and physically, to help save these cute animals! #BIO227Fall2015

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